U23F-01 INVITED
Melting and surface mass balance over the Greenland ice sheet from satellite data, model results and ground measurements during IPY: extreme events and updated trends.
The International Polar Year is offering a unique opportunity for demonstrating, following and getting involved with cutting-edge science. Many projects have been selected and many others have been stimulated and pushed forward by the discussions, results and new questions arising from the many collaborations within the IPY framework. In this study, we report results regarding an ongoing collaboration for improving snowmelt detection and surface mass balance estimation over the Greenland ice sheet from combined satellite data, model results and ground measurements. In particular, passive microwave observations are used to derived melt extent and duration over the entire Greenland ice sheet on a daily basis. These results are then compared with those obtained with a regional model (MAR), with the modeled net surface energy fluxes and with the trends of surface temperature collected along the coast at selected locations. Surface mass balance data of the Greenland ice sheet is also derived from the MAR model and compared with those from ground measuerements performed on the ablation zone of the west Greenland ice sheet along the 67° N latitude circle, at distances of 6, 38 and 88 km from the ice sheet margin at elevations of 490, 1020 and 1520 m a.s.l. Results are updated through the 2008 melting season and evaluated in the context of the 1979 – 2008 period. Satellite results show that 2008 was in agreement with the recently observed increase of melting over the Greenland ice sheet. Moreover, model results suggest a negative surface mass balance for the second year in a row, comparable to or lower than that modeled for 2007. Ground results are being analyzed at the moment of abstract submission and will be reported during the talk.
U23F-02 INVITED
The International Polar Year (IPY) Circumpolar Flaw Lead (CFL) System Study
The International Polar Year (IPY) Circumpolar Flaw Lead (CFL) system study supported a large multidisciplinary overwintering in the Banks Island (NT) flaw lead over the period September 2007 to August 2008. The CFL system is formed when the central pack ice (which is mobile) moves away from coastal fast ice, opening a flaw lead. The CFL forms in the fall and continues as thin ice or open water throughout the winter. The flaw lead is circumpolar, with recurrent and interconnected polynyas occurring throughout the Arctic. The overarching objectives of the CFL project were to contrast the physical and biological systems of the flaw lead open water and thin ice to the adjacent landfast ice cover. The Canadian Research Icebreaker (NGCC Amundsen) completed the first-ever overwintering of a research icebreaker in the flaw lead. She supported a total of 11,000 person days distributed across 295 investigators from 28 different countries, making the CFL project the largest single IPY effort in the northern hemisphere. The project obtained many first-ever measurements of a complete suite of physical, biogeochemical, contaminant and marine ecosystem variables across the open water - fast ice contrast. Throughout the project we recognized that Inuvialuit and western science have two different ways of understanding the dramatic changes that are occurring in this sector of the Arctic. This 'two-ways-of-knowing' saw the integration of traditional knowledge studies with the science teams onboard the Amundsen. We present information on the design of the project, an overview of the sampling program completed, highlight the scientific programs conducted, and provide some preliminary results. We conclude with an overview of the various outreach programs including a World Federation of Science Journalists (WFSJ) competition and 'Schools on Board' programs.
U23F-03
International Siberian Shelf Study 2008 (ISSS-08): The major IPY ship-based program along the entire Eurasian-Arctic continental shelf with combined biogeochemical and geophysical observations
The coastal margin north of Eurasia is the world's largest continental shelf. It provides an important regime for transport and processing of heat, freshwater and carbon between its Siberian drainage basins and the high Arctic Ocean. There are gradients in climate and carbon dynamics along the Barents, Kara, Laptev, East Siberian, and Chuckchi Sea conduits. The continent-scale system is characterized by strong discharge through the Great Russian Arctic Rivers, onshore and offshore-subsea permafrost with massive shallow methane deposits, eroding carbon-rich coasts, and shelf-feeding of the Arctic halocline. The region is of particular interest from the perspective of carbon-climate couplings. Surface air temperature anomalies for 2000--2005 in the East Siberia are about 4°C higher than preceding 30-year average. Hence, there is a potential for remobilization of 'old' terrestrial carbon from thawing tundra permafrost and coastal-ice complexes as well as methane release from subsea permafrost. The role of climate warming on shelf-derived halocline waters has also yet to be elucidated. The 50-day Russia-Sweden-USA expedition onboard H/V Jacob Smirnitsky presented a golden opportunity to shed lights on these issues. A second ISSS-08 component investigated in detail the Lena river and the shallow Laptev Sea. The ISSS-08 had a particular geographical focus on the Laptev, East Siberian and Russian-sector of Chukchi Sea as this is the most enigmatic and under-sampled region in the Arctic ocean. A multitude of complementary studies were carried out. Underway sampling of 4 m seawater was continuously monitored for a broad range of geophysical and biogeochemical parameters; air was continuously sampled for CH4 stable isotopes, aerosols and met properties including air-sea CO2 and CH4 turbulent fluxes . Detailed stations for sediment, water, and air were occupied off the river mouths of Ob, Yenisey, Lena, Indigirka and Kolyma. Five polygons outside sites of intense coastal erosion were occupied. Transects were taken along the Lena and Kolyma paleocanyons, including seismic profiling. Significant findings already during the expedition included discovery of several new areas of substantial methane seeps in both the Laptev and East Siberian Sea. We also recorded Pacific inflow through the Herald Canyon and remnants still in September of salty and cold bottom waters on the East Siberian Sea shelf break. A multitude of further analysis of collected seawater and sediment material is planned, including detailed molecular biomarkers composition and compound-specific radiocarbon analysis as well as trace element and isotope characterizations to elucidate provenance, extent of remobilization of 'old' terrestrial matter, the relative importance of river versus erosion sources, degradation of organic matter in the water column and in sediments, as well as variations in these processes with dynamic climate forcings. The complex expedition was a success and we anticipate future ISSS expeditions.
U23F-04 INVITED
Projected Arctic warming, rapid sea ice loss, and snow state changes: Influence on near- surface permafrost degradation
Projected climatic changes in the Arctic associated with increasing greenhouse gas concentrations are varied. Global climate models suggest that warming in the Arctic will be considerably stronger than the rest of the world. In the Community Climate System Model (CCSM3), 21st century terrestrial Arctic warming ranges from ~+4 to +8° C depending on emission scenario. This warming is non-linear, due in part, to periods of accelerated sea ice loss. Along with the warming, CCSM3 (and other global models) project an increase in winter snowfall and concomitant changes in snow depth, snow density, and snow-season length. Here, we evaluate the roles of Arctic warming, accelerated sea ice loss, and snow state changes on the rate and extent of soil warming and permafrost degradation. We utilize the Community Land Model (CLM) with improved permafrost dynamics to evaluate and compare the large-scale near-surface permafrost response to these climatic forcings. The strong projected warming is, not surprisingly the biggest contributor to permafrost degradation. However, we can attribute roughly 18 percent of the permafrost degradation to increasing snowfall and the resulting maintenance of the insulating snowpack even in the face of strong warming. We also find that a period of accelerated warming associated with rapid sea ice loss can accelerate soil warming and lead to rapid thaw of warmer permafrost and to increased vulnerability of colder permafrost.
U23F-05 INVITED
The Greening of the Arctic IPY Project
In 2007, Arctic sea ice extent declined to the lowest level in recorded history, 24 percent lower than the
previous record in 2005. If the Arctic continues to warm over the next few decades as predicted by most
arctic scientists, large changes in vegetation biomass will occur and will have important consequences to
many components of the Arctic system including status of the permafrost, hydrological cycles, wildlife, and
human occupation. There will also be important feedbacks to climate through changes in albedo and carbon
fluxes. Changes in biomass are already happening. In Arctic Alaska from 1981 to 2001, the greenness of the
landscapes as measured by satellite-derived values of the normalized difference vegetation index (NDVI)
increased by 17 percent. It is uncertain what this remarkable change in greenness means with respect to
plant biomass, but current NDVI-biomass relationships suggest that an average of over 100 g m-2 have been
added to the tundra of northern Alaska within the past twenty years. Other studies have shown a major
increase of shrub cover across northern Alaska during the past 50 years. If the Arctic Ocean becomes ice-
free during the summer, some of the largest percentage increases could occur in the coldest parts of the
Arctic. The three major objectives of this project are: (1) establish baseline ground observations along two
transects in North American and Eurasia that traverse the entire Arctic bioclimate gradient; (2) use remote
sensing and climate change analysis to determine how changes in sea ice concentrations affect land-surface
temperature and the NDVI, (3) use vegetation-change models to predict how vegetation will change in the
future. Strong correlations exist between sea-ice concentrations, land-surface temperatures, and the
maximum and integrated NDVI). The changes in greening have been strongest in the Beaufort Sea region.
Between 1982 and 2007, sea ice in the 50-km coastal strip of Beaufort Sea area during the period 18 June -
22 July decreased -5.8 percent / decade. Land-surface temperatures (as indicated by the summer warmth
index (SWI), showed a corresponding increase (1.56 degree C mo / decade). The greening response of the
vegetation (as indicated by the summer maximum NDVI and the total integrated NDVI) increased 0.051 and
0.25 / decade respectively. Sea ice concentrations and SWI were negatively correlated and the SWI and
integrated NDVI were positively correlated. These trends are consistent with all other coastal areas studied in
the Arctic â€" i.e., periods of lower sea-ice concentration are correlated with warmer land-surface
temperatures and higher NDVI values. The sea-ice and land-surface trends are also much strong in the E.
Siberian and Chukchi sectors of the Russian Arctic (less than -10 percent / decade respectively and greater
than 2.2 degree C / decade). Climatically, summer warmth trends in the Beaufort region showed a significant
positive correlation with the North Atlantic Oscillation (NAO) during the December to March period of the
preceding winter. Sea ice trends showed a weak negative correlation with the Pacific Decadal Oscillation
(PDO).
http://www.geobotany.uaf.edu/goa/
U23F-06
ASCOS - the "Arctic Summer Cloud-Ocean Study"
Understanding the effects of clouds on climate still constitute one of the largest challenges and this is
perhaps more true in the Arctic than elsewhere. Clouds have the single largest impact on the surface energy
budget and thus control a significant fraction of the melting and freezing of sea ice. At the same time, we
know less of about cloud formation in the Arctic than elsewhere; this fact is also reflected in modeling results
for the Arctic.
ASCOS is an interdisciplinary experimental program, with its field phase in the central Arctic onboard the
Swedish icebreaker Oden during August and early September 2008; the timing was chosen to bee during the
late summer melt and into the intial surface freeze.
Within ASCOS seventeen research groups from eleven countries, with fourteen nationalities, came together
to attempt understanding the formation of Arctic summer clouds, their impact on summer melt and initiation of
the surface freeze up. ASCOS is among the broadest projects in IPY. ASCOS brings marine biology and
chemistry, physical oceanography, meteorology, atmospheric gas phase and particulate chemistry and
physics into the same experiment to observe aerosols, cloud condensation and ice nuclei formation, cloud
formation, interaction between clouds and surface energy balance and with larger scale weather.
Observations were performed on board the ice breaker and on the ice during a three week ice drift, by in situ
or remote sensing instruments.
ASCOS is an IPY program under the umbrella of AICI-IPY, and is affiliated with several other IPY project, and
is also a part of DAMOCLESA. The presentation will provide a brief overview of ASCOS and show examples
of the benefits of the interdisciplinary and international approach of ASCOS.
http://www.ascos.se
U23F-07 INVITED
Scientific Data as the Core Legacy of IPY
The interdisciplinary breadth of the International Polar Year is unprecedented. The IPY has explicit objectives
to link researchers across different fields to address questions and issues lying beyond the scope of
individual disciplines and to strengthen international coordination of research and enhance international
collaboration and cooperation. The IPY Data Policy and Management Subcommittee have developed a policy
to help meet these objectives and an international collaboration of investigators and data managers, the IPY
Data and Information Service, are working to make IPY data widely available. I will present an overview of the
primary data management considerations for IPY and how diverse organizations are making IPY and related
data available. Centralized discovery mechanisms for widely distributed data plus targeted access
mechanisms for specific disciplines will be presented. These range from near real time access to satellite
remote sensing data and GCM output to fair and appropriate access to traditional knowledge of the Arctic.
These mechanisms reflect significant advancement in polar data management, but they belie the major
challenges that remain. These challenges include fostering a culture change in science that puts greater
value on data publication and open data access as well as developing sustained systems and business
models for the long-term preservation of IPY data. This will be crucial to ensuring the legacy of IPY, a major
objective of IPY sponsors, ICSU and WMO. New efforts to ensure this legacy include the development of the
WMO Information System, the Sustained Arctic Observing Network, and the Global Earth Observing System
of Systems; the reform of ICSU's World Data Center System; and the results of the Electronic Geophysical
Year.
http://ipydis.org
U23F-08 INVITED
Providing a Continuum of Leadership in Polar Science – An IPY Legacy
The Association of Polar Early Career Scientists (APECS) grew out of the 4th International Polar Year (IPY-4)
2007-08 and is an international and interdisciplinary organization of over 1200 undergraduate and graduate
students, postdoctoral researchers, early faculty members, educators and others with interests in Polar
Regions and the wider cryosphere from more than 40 countries. Our aims are to stimulate interdisciplinary
and international research collaborations, and develop effective future leaders in polar research, education
and outreach.
As potentially one of the major legacies of IPY-4, APECS members have been at the forefront of increasing
scientific knowledge and public interest in the polar regions, centered around global climate change, and
enhancing scientific understanding, media attention, primary and secondary school (K-12) educational
programs, and public literacy campaigns. Research and Educational Outreach activities by APECS members
during IPY-4 have improved both our understanding and the communication of all aspects of the Polar
Regions and the importance of their broader global connections. APECS National Committees have run Polar
Contests where young researchers partnered with teachers and students to develop curriculum and
activities to share their research, have participated in many field based communication exchanges and are
mentoring youth to pursue careers in science, and enhancing the public perception of scientists through
photo, video and museum exhibits.
In cooperation with the IPY Teachers Network and the IPY IPO, APECS is developing a polar education
resource book that will feature education and outreach activities by young researchers, as well as provide
examples of classroom activities for teachers to incorporate polar literacy into their curriculum and a 'how to'
guide for researchers interested in conducting education and outreach.
As young researchers share their excitement and experiences in deepening our understanding of the polar
regions, a new generation of polar literate people emerges and society benefits from more knowledge of the
rapidly changing polar regions that have a critical and inherent global connection.
http://www.apecs.is